1. Field
Example embodiments relate to methods of manufacturing semiconductor devices. More particularly, example embodiments relate to methods of manufacturing semiconductor devices including buried gate structures.
2. Description of the Related Art
As semiconductor devices have become more highly integrated, improved methods of forming fine patterns have been developed. However, reducing the size of certain features, such as transistor gate length, can have undesirable consequences. Accordingly, transistors having buried gate structures may be used in order to increase a channel length in a highly integrated device.
After forming the buried gate structure, subsequent processes, such as a cleaning process, an annealing process and/or an oxidation process for forming a gate structure in a peripheral circuit region may be further performed. During the subsequent processes, the buried gate structure may be adversely affected by oxide diffusion, etching damage, etc.